I was under the impression for quite a while that Elite's ships used some kind of ion propulsion, and the hydrogen fuel kept onboard was just used to power a fusion power plant, which in turn provided the necessary power for the ion thrusters. That would explain why ships in 3300 can only achieve relatively slow speeds (and are always blue) in comparison to modern day spaceships; relativistic speeds and FTL are handled by the FSD, after all. Now, we have the ability to color our thrusters, which, as far as I know, doesn't make sense as far as ion thrust goes, so that leaves chemical thrusters as the solution, possibly using liquid hydrogen as fuel. This doesn't make any sense though, since liquid hydrogen engines are supposed to be extremely powerful, and any ship using them should be able to achieve much higher speeds than they do in game. Thoughts?